DNA barcoding of Malaysian marine fish, phylogenetics and phylogeography of the snappers (Perciformers: Lutjanidae) (IR)

This study, implemented DNA Barcoding which offers great potential as a reliable identification tool to classify catches in Malaysia. Overall, this study had successfully barcoded a total of 107 species, 69 genera, 36 families and 10 order of commercial Malaysian fishes. It is found that, the snappe...

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Bibliographic Details
Main Author: Adibah Abu Bakar
Format: thesis
Language:zsm
Published: 2017
Subjects:
Online Access:https://ir.upsi.edu.my/detailsg.php?det=3660
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Summary:This study, implemented DNA Barcoding which offers great potential as a reliable identification tool to classify catches in Malaysia. Overall, this study had successfully barcoded a total of 107 species, 69 genera, 36 families and 10 order of commercial Malaysian fishes. It is found that, the snappers, threadfin fishes, parrot fishes and goatfishes sampled were detected to either experience cryptic speciation or consist of unknown/undescribed species. Conventional identification to species level using morphological characters were found to be difficult for this genera especially in cases where juvenile and adult specimens exhibit variation in colouration. Using COl gene, deep genetic divergence (K2P = 6.1%) values was obtained between LLI and LL2 groups of L. lutjanus and the subsequent analysis of both COl and cyt b sequences revealed diagnostic nucleotide substitution sites exclusively to each group. Thus, at present, this study exposed that at least one lineage represents a currently unrecognized taxon of the 'yellow-lined snapper complex'. A total of 3612 bp aligned sequences corresponding to the combinations of two mitochondrial genes (654 bp of the COl gene and 1116 bp of cyt b gene) and two nuclear genes (897 bp of the RH gene and 945 bp of the EGRI gene) were also employed to reconstruct a comprehensive phylogenetic framework of the Lutjanidae. Results from current study did indicate that lutjanids presented a non-reciprocal monophyletic distribution within Eastern Pacific (EP), Indian Ocean (10), Indo-Pacific (lP) and Western Atlantic (WA) regions. Using a fossil-based calibration to constraint the relaxed molecular clock model for biogeography analysis in current research, it is found that WA, EP and 10 lutjanids derived from Indo-Pacific lineages